I've always had an air purfiier as a dog/cat owner with allergies. The difference between this and the rest I've owned is insane. It's bigger, so it covers more ground. It has a filter that lasts 5 years with removable screens to clean out the grime, which is an absolute GAME CHANGER for me. It also tracks the particles it is filtering in and has a space for a deodorizer. This machine truly does it all and I am so, so impressed. I'm breathing and feeling better after one week of use.